Thin-film-transistor (TFT)/liquid crystal (LC) antenna apertures may be formed in a single TFT/LC panel. This requires that the mother glass in the TFT/LC panel fabrication be large enough to accommodate the entire active area, the routing, connection area, seal area, etc. A TFT/LC fabrication facility is a highly tuned line of machinery that operates efficiently at a set throughput, with all equipment in the line matched to this throughput. Therefore, the capital outlay of building such a facility and populating it with equipment is very large.
Unfortunately, TFT/LC aperture fabrication utilizes some processes that are not easily accommodated by existing TFT/LCD fabrication facilities. That is, by performing these steps, the fabrication facility, line, etc. are disrupted, harming the set throughput of the manufacturing line. Therefore, making an antenna aperture with a single TFT/LC panel is inefficient, reduces fabrication throughput, and significantly raises the manufacturing costs of the resulting TFT/LC aperture.
Several mitigations to improve efficiencies and reduce the cost impact on a TFT/LC manufacturing operation are possible. One such mitigation would be to add to the manufacturing line facilities and equipment that can provide manufacturing capacity in the processing steps required by the TFT/LC aperture, so that the throughput of TFT/LC apertures in these steps could match that of the rest of the facility. For a recent generation TFT/LC facility, with a mother glass capable of making the TFT/LC RF aperture in one piece, this capital outlay would be prohibitively large.
A less capital intensive alternative is to produce the TFT/LC RF apertures on older generation, underutilized, and mostly deprecated TFT/LC fabrication equipment. Due to underutilization and the depreciated nature of such fabrication facilities, the impact of unbalancing the line is not as expensive as in a more recent generation fabrication facility. Additionally, building capacity in the required steps is not as capital intensive due to the smaller sizes of the mother glass. Also, some capacity in the manufacturing operations may be obtained from the outside suppliers. However, the mother glass sizes of these older generation fabrication facilities are not large enough to build the TFT/LC RF apertures on one mother glass.